# V3003\. The use of 'if \(A\) \{\.\.\.\} else if \(A\) \{\.\.\.\}' pattern was detected\. There is a probability of logical error presence\.

The analyzer has detected a potential error in a construct consisting of conditional statements\.

Consider the following example:

```cpp
if (a == 1)
  Foo1();
else if (a == 2)
  Foo2();
else if (a == 1)
  Foo3();
```

In this code, the 'Foo3\(\)' method will never get control\. We are most likely dealing with a logical error here and the correct version of this code should look as follows:

```cpp
if (a == 1)
  Foo1();
else if (a == 2)
  Foo2();
else if (a == 3)
  Foo3();
```

In practice though, errors of this type can take more complicated forms, as shown below\.

For example, the analyzer has found the following incorrect construct\. 

```cpp
....
} else if (b.NodeType == ExpressionType.Or || 
           b.NodeType == ExpressionType.OrEqual){
                   current.Condition = ConstraintType.Or;
} else if(...) { 
.... 
} else if (b.NodeType == ExpressionType.OrEqual ||
           b.NodeType == ExpressionType.Or){
                   current.Condition = ConstraintType.Or | 
                   ConstraintType.Equal;
} else if(....
```

In this example, the uppermost if statement checks the following condition: 

```cpp
b.NodeType == ExpressionType.Or || 
b.NodeType == ExpressionType.OrEqual.
```

while the lowermost if statement checks a condition with the same logic but written in a reverse order, which is hardly noticeable for a human yet results in a runtime error\.

```cpp
b.NodeType == ExpressionType.OrEqual ||  
b.NodeType == ExpressionType.Or
```